topic 1:atoms,molecules & ions

What are the 3 particles that make-up the atom?

• protons, neutrons, and isotopes
• neutrons, isotopes, and electrons
• positives, negatives, and electrons
• protons, neutrons, and electrons

Tags

NGSS.MS-PS1-1

Two or more atoms chemically bonded together are called a

• atom
• element
• molecule
• mixture

Tags

NGSS.MS-PS1-1

There are ________ electrons, ________ protons, and ________ neutrons in an atom of Xe.

• 132, 132, 54

• 54, 54, 132

• 78, 78, 54

• 54, 54, 78

• 78, 78, 132

The average atomic weight of copper, which has two naturally occurring isotopes, is 63.5. One of the isotopes has an atomic weight of 62.9 amu and constitutes 69.1% of the copper isotopes. The other isotope has an abundance of 30.9%. The atomic weight (amu) of the second isotope is ________ amu.

• 63.2

• 63.8

• 64.1

• 64.8

• 28.1

What is the mass number of bromine?

• 35

• 45

• 80

• 79.904

How many neutrons does this Neon atom have?

• 21

• 11

• 10

• 12

Tags

NGSS.MS-PS1-1

Which part of an atom is POSITIVELY charged?

• protons
• neutrons
• electrons
• atoms

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%
• 27%
• 46%
• 53%

How many molecules are in 2.5 mol of NaCl?

• 1.5 x 10²⁴ molecules

• 1.5 molecules

• 4.15 molecules

• 1.5 x 10²³ molecules